Molybdenum compounds are known to be useful as friction modifiers in lubricating oil compositions. However, many molybdenum compounds exhibit poor solubility in lubricating oils. Molybdenum disulfide, a commonly used lubricant additive, has poor solubility in oil and various methods including fine grinding and dispersing agents have been employed to improve its effectiveness in lubricating oils.
A number of alternative approaches have been proposed for the incorporation of molybdenum in lubricating oils. In general, these approaches involve preparing complex reaction products containing molybdenum which exhibit improved solubility of the molybdenum-containing complex in lubricating oils.